Main Characters
Ibuki
Designed and played by: Shimadoriru
Voiced by: Marina Inoue (Japanese), Ryan Reynolds (English)
The true protagonist of the anime, Ibuki was born with a twin sister as the descendants of the imperial line, which once ruled Nill Kamui. Hated by society thanks to the prophecies of an oracle, Ibuki would have been destined for execution if not for the intervention of his mother Hana Guya, who arranged for her child to go into hiding with his grandparents. One day, he was awakened to the tragedies of the world when he met the Red Dragon. Ibuki despaired, but knowing his true heritage, he joined the Revolutionary Army in hopes of changing the world for the better.
- Overshadowed by Awesome: Luo and Swallow tend to hog the spotlight when they're around.
- Power at a Price: In the anime, he can only really fight through his contract with Red Dragon. He has to sacrifice a person he cares about, but gains incredible power for a short time.
- Platonic Life-Partners: With Eiha.
- Survivor Guilt: After Red Dragon's first rampage, he is apparently the only survivor. Some of the victims do resurrect, though.
Eiha
Designed and played by: Kougyoku Izuki
Voiced by: Miyuki Sawashiro (Japanese), Mary Morgan (English)
A young girl who lives as a "Bound One", Eiha is one of a race of peoples native to the island, bonded from birth to ferocious monsters by vine-like chains. Her life is bound to Val, a huge canine creature with bat-like wings but no eyes. Living like an animal in the wild, she was abducted by humans and made to serve noble after noble, until one day she met another Bound One named Juna, and joined the Revolutionary Army.
- Action Girl: She is the only female in main character roster.
- Age-Inappropriate Dress: More pronounced in the original illustrations than in the TV series.
- Badass Adorable: She is only 10.
- Beware the Quiet Ones
- Big Damn Heroes: To Agito.
- Cat Girl: She has cat ears.
- Curb-Stomp Battle: Val just gobbles up Agito's would-be assassins in her first on-screen battle in the game session.
- Deuteragonist: To Ibuki.
- Emotionless Girl: Because she was a slave, she is very cold towards other people.
- Image Song: Beast Song by MiyukiSawashiro.
- One-Hit Kill: Val's attacks Agito's would-be assassins are these.
- Platonic Life-Partners: With Ibuki.
- Stripperiffic: Her original design.
- Unusual Ears: Possesses animal ears.
- Your Days Are Numbered: Bound Ones can't live until above 16.
Swallow Kratzvalley
Designed and played by: Kinoko Nasu
Voiced by: Soma Saito (Japanese), Orion Pitts (English)
Swallow is a young noble member of the Black Dragon Knights, the D'natian Empire's greatest knightly order. He is bound by a curse of Pulverization, which destroys any tools he uses with his hands. After forming a True Pact with his order's patron deity, the Black Dragon, Swallow gains the power to oppose the Seven Dragons themselves, in order to subjugate the rampaging Red Dragon. Together with his servant Meryll, he joins the international Joint Investigation Task Force and sets off for the island of Nill Kamui.
- All There in the Manual: His backstory, personal traits, and concepts are only found in the Red Dragon Character Material, though included in the anime.
- Attention Whore: Nasu wants him to be an annoying character.
- Awesome, but Impractical: His Curse of Pulverization makes each of his attacks this. It is VERY STRONG, but the sword he used is destroyed immediately afterwards. As such, Meryll must provide many swords in advance... using her own money (because Swallow is very poor).
- Battle Couple: With Meryll.
- BFS: His Black Blade skill.
- Casanova Wannabe: Meryll is not amused by this.
- Character Alignment: Lawful Good.
- The Corruptible: Enchanted by the Qisha Tienling in one scene.
- Dark and Troubled Past: In his childhood, he is imprisoned because of his Curse.
- Deal with the Devil: [[spoiler His contract with the Black Dragon can be considered this. If he fails to defeat Red Dragon, he will die. But if he succeeds, his wish will be fulfilled.]]
- Everyone Can See It: His relationship with Meryll. It's not blatantly romantic, but their feelings toward each other are noted by other characters.
- Foil: To Luo.
- For Happiness: Swallow only wants Meryll to be happy without him.
- Hair of Gold, Heart of Gold: Typical of Nasu.
- Healing Factor: His job, the Dark Dragon Knight, allows him to recover health slowly.
- Heroes Prefer Swords: His weapon is broadsword.
- Hidden Depths: Turns out to be very philosophical. Mainly because he's being played by Nasu.
- Idiot Hero: Meryll even calls him "trash" and "scum" because of his stupidity.
- Impossibly Cool Clothes: His original design.
- Knight in Shining Armor: His armor is black, but he is very chivalrous.
- Living Emotional Crutch: To Meryll.
- Mega Manning: His Curse of Pulverization with True Pact activated.
- Nice Guy: He's friendly towards everybody and constantly tries to make friends, even with people who are clearly hostile towards him.
- Nice Job Breaking It, Hero: The infamous plane accident. Because of his Curse, the plane overcomes all of its limits... but of course it crashes afterwards. Spectacularly.
- Odd Friendship: With Ibuki.
- One-Hit Kill: His curse guarantees a lot of these, despite the downside.
- Rivals Team Up: With Luo.
- Rule of Cool: His original armor. Point of note: his greaves and scabbards on hip.
- Scary Impractical Armor: The greaves he wore in the game session art were a lot more beefed up than they became in the anime.
- Ship Tease: With Meryll. His feelings are pretty much reciprocated.
- Superpower Lottery: The Curse of Pulverization. The Curse triples the effectiveness of any weapons he use, but instantly destroy them after that. It also manifests on other things beside weapons. This curse also likely the cause of the bankruptcy of his clan.
- Sword Beam: The Black Blade skill. Actually, it's a black Excalibur.
- Wild Hair: Styled like dog's ears.
- Worthy Opponent: To Luo.
Luo Zhenjie/Luo Zhenfa
Designed and played by: Gen Urobuchi
Voiced by: Maaya Uchida (Japanese), Michelle Rojas (English)
The warrior monk Luo comes from a religious sect in Huanglan, one of the world's two great powers opposite D'natia. With the guidance of his sentient, demonic sword Qisha Tianling, he is an accomplished assassin. His well-known reputation for killing any and all targets has earned Luo an ominous reputation in the underworld. He only measures a person's worth by whether it would be worthwhile to kill them, and uses his unique ability to keenly observe subjects even in his peripheral vision to calculate the perfect time to strike.
In the anime, he is genderflipped.
- Ax-Crazy: After his death, he isn't even hiding this anymore.
- Badass Cape: Luo's original design sports this.
- Body Horror: After his bisection, you can still see his stomach wound.
- Brutal Honesty: To Swallow, "You're hated by your tools."
- Came Back Wrong: After being split in two in the game session, he returns as a zombie because of Nill Kamui's spiritual property.
- Combat Stilettos: Female Luo's spiked high-heels.
- Deal with the Devil: Tisha Qianling can be considered this, because it is a demonic sword.
- Death by Irony: Meta example. Given Urobuchi's tendency to be Urobuchi, the other players conspired against him, pulling bluff after bluff after bluff to screw him over. As a result, Luo winds up chopped in half.
- The Dreaded: Because he is created by Urobuchi, all players are wary of him.
- Energy Absorption: Qisha Tianling eats mana and souls.
- Foil: To Swallow.
- Foreshadowing: Considering Urobuchi's past record...
- Gender Flip: Becomes a woman in the anime.
- Half the Man He Used to Be: Simeon cuts him in half with an absolutely ENORMOUS sword. However, he still returns as an undead leader with his two halves stitched together.
- In the Hood: 'Her' new design for the anime features a hood.
- Malevolent Masked Man: After his resurrection.
- Mystical White Hair: Female Luo.
- Not Quite Dead: Resurrected because he died in Nill Kamui, where the dead can return to life again.
- Obviously Evil: Let's see. A full-black outfit. A demonic sword. Played by Gen Urobuchi...
- Our Zombies Are Different: Returns as a zombie after Simeon cut him in half.
- Perpetual Frowner: Male Luo.
- Psychotic Smirk: Female Luo's standard expression.
- The Stoic: Male Luo.
- The Tease: Funnily, she teases Swallow a lot.
- Worthy Opponent: To Swallow.
- White Hair, Black Heart: 'Her' new design.
Kaguraba
Designed and played by: Ryohgo Narita
Voiced by: Unshō Ishizuka (Japanese), Mike McFarland (English)
A trader whose work has carried him all across the world, Kaguraba is known as the Immortal Merchant.
- Cyborg: Has replaced almost his entire body with robotic parts. Whether he's gone full Brain in a Jar is not known.
- Knowledge Broker: His network of business relationships allows him to keep in tune with what's going on.
- Shipper on Deck: To Swallow. "Your bond with Meryll is an eternal one."
Meryll Sherbett
Designed and played by: Nasu Kinoko, played by the Fiction Master
Voiced by: Haruka Terui (Japanese), Caitlin Glass (English)
Swallow's personal servant aka maid, also the owner of Sherbett merchant company. Swallow saved her from slavery back in her childhood, and since then, harbors very deep feelings to him. But, an incident in her teenage years may have changed that feeling.
- Battle Couple: With Swallow.
- Meido: As usual from Nasu.
- Ship Tease: With Swallow. Her feelings are pretty much reciprocated, with Swallow declaring that Meryll is his "most important property".
- Tsundere: She mocks Swallow as "scum" or "trash", but she's actually very concerned about him.
D'Natia
Ulrika Ledesma
Voiced by: Aimi Terakawa (Japanese), Alexis Tipton (English)
A Black Dragon Knight of D'natia, ranked 22nd.
- Action Girl: She's a nigh-unkillable fighter and holds her own against Lou.
- Dark Is Not Evil: As with most of the Black Dragon Knights, she wears black armor and is associated with darkness, and also keeps a hydra in her shadow, but she's a kind person.
- Expy: Her resemblance to Saber from Fate/stay night is almost uncanny.
- Off with Her Head!: Lou cuts off her head, then keeps it to throw at Simeon (in the game session) or Swallow (in the anime.
Simeon Tsalikov
Voiced by: Keiji Fujiwara (Japanese), Marcus D. Stimac (English)
A Black Dragon Knight of D'Natia, ranked 3rd, Simeon is D'natia's highest authority on Nill Kamui
- Authority Equals Asskicking: D'natia's highest authority on the island and their most powerful soldier as well.
- BFS: Wields a huge black sword, which grows even bigger through his contract with Black Dragon.
- Large and in Charge: He's taller and has a broader chest than most of the other characters. He's also D'natia's highest authority on the island.